<!-- 城市 -->
<template>
    <div class="city_body">
        <div class="city_list">
            <Loading v-if="isLoading" />
            <Scroller v-else ref="city_List">
                <div>
                    <div class="city_hot">
                        <h2>热门城市</h2>
                        <ul class="clearfix">
                            <li
                                v-for="item in hotList"
                                :key="item.id"
                                @tap="handleToCity(item.nm, item.id)"
                            >
                                {{ item.nm }}
                            </li>
                        </ul>
                    </div>
                    <div class="city_sort" ref="city_sort">
                        <div v-for="item in cityList" :key="item.index">
                            <h2>{{ item.index }}</h2>
                            <ul>
                                <li
                                    v-for="itemList in item.list"
                                    :key="itemList.id"
                                    @tap="
                                        handleToCity(itemList.nm, itemList.id)
                                    "
                                >
                                    {{ itemList.nm }}
                                </li>
                            </ul>
                        </div>
                    </div>
                </div>
            </Scroller>
        </div>
        <div class="city_index">
            <ul>
                <li
                    v-for="(item, index) in cityList"
                    :key="item.index"
                    @touchstart="handleToIndex(index)"
                >
                    {{ item.index }}
                </li>
            </ul>
        </div>
    </div>
</template>

<script>
//这里可以导入其他文件（比如：组件，工具js，第三方插件js，json文件，图片文件等等）
//例如：import 《组件名称》 from '《组件路径》';

export default {
    //import引入的组件需要注入到对象中才能使用
    name: 'City',
    props: {},
    components: {

    },
    data () {
        //这里存放数据
        return {
            cityList: [],
            hotList: [],
            isLoading: true
        };
    },
    //监听属性 类似于data概念
    computed: {},
    //监控data中的数据变化
    watch: {},
    //方法集合
    methods: {
        formatCityList (cities) {
            var cityList = [];
            var hotList = [];
            for (var i = 0; i < cities.length; i++) {
                if (cities[i].isHot === 1) {
                    hotList.push(cities[i])
                }
            }
            for (var i = 0; i < cities.length; i++) {
                var firstLetter = cities[i].py.substring(0, 1).toUpperCase()
                if (toCom(firstLetter)) {
                    cityList.push({ index: firstLetter, list: [{ nm: cities[i].nm, id: cities[i].id }] })
                } else {
                    for (var j = 0; j < cityList.length; j++) {
                        if (cityList[j].index === firstLetter) {
                            cityList[j].list.push({ nm: cities[i].nm, id: cities[i].id })
                        }
                    }
                }
            }
            cityList.sort((n1, n2) => {
                if (n1.index > n2.index) {
                    return 1
                } else if (n1.index < n2.index) {
                    return -1
                } else {
                    return 0
                }
            })
            function toCom (firstLetter) {
                for (var i = 0; i < cityList.length; i++) {
                    if (cityList[i].index === firstLetter) {
                        return false;
                    }
                }
                return true;
            }
            return { cityList, hotList }

        },
        handleToIndex (index) {
            var h2 = this.$refs.city_sort.getElementsByTagName('h2')
            // this.$refs.city_sort.parentNode.scrollTop = h2[index].offsetTop
            this.$refs.city_List.toScrollTop(-h2[index].offsetTop)

        },
        handleToCity (nm, id) {
            this.$store.commit('city/CITY_INFO', { nm, id })
            window.localStorage.setItem('nowNm', nm)
            window.localStorage.setItem('nowId', id)
            this.$router.push('/movie/nowPlaying')
        }
    },
    //生命周期 - 创建完成（可以访问当前this实例）
    created () {

    },
    //生命周期 - 挂载完成（可以访问DOM元素）
    mounted () {
        var cityList = window.localStorage.getItem('cityList')
        var hotList = window.localStorage.getItem('hotList')
        if (cityList && hotList) {
            this.cityList = JSON.parse(cityList);
            this.hotList = JSON.parse(hotList);
            this.isLoading = false
        } else {
            this.axios.get('/api/cityList').then(res => {
                let msg = res.data.msg;
                if (msg === 'ok') {
                    this.isLoading = false
                    var cities = res.data.data.cities
                    // [{index:'A',list:[{nm:'A城',id:123}]}]将获取的数据重新排列新格式
                    var { cityList, hotList } = this.formatCityList(cities)
                    this.cityList = cityList
                    this.hotList = hotList
                    window.localStorage.setItem('cityList', JSON.stringify(cityList))
                    window.localStorage.setItem('hotList', JSON.stringify(hotList))
                }
            })
        }

    }

}
</script>
<style lang='scss' scoped>
// @import url(); 引入公共css类
#content .city_body {
    margin-top: 45px;
    display: flex;
    width: 100%;
    position: absolute;
    top: 0;
    bottom: 0;
}
.city_body .city_list {
    flex: 1;
    overflow: auto;
    background: #fff5f0;
}
.city_body .city_list::-webkit-scrollbar {
    background-color: transparent;
    width: 0;
}
.city_body .city_hot {
    margin-top: 20px;
}
.city_body .city_hot h2 {
    padding-left: 15px;
    line-height: 30px;
    font-size: 14px;
    background: #f0f0f0;
    font-weight: normal;
}

.city_body .city_hot ul li {
    float: left;
    background: #fff;
    width: 29%;
    height: 33px;
    margin-top: 15px;
    margin-left: 3%;
    padding: 0 4px;
    border: 1px solid #e6e6e6;
    border-radius: 3px;
    line-height: 33px;
    text-align: center;
    box-sizing: border-box;
}

.city_body .city_sort div {
    margin-top: 20px;
}
.city_body .city_sort h2 {
    padding-left: 15px;
    line-height: 30px;
    font-size: 14px;
    background: #f0f0f0;
    font-weight: normal;
}
.city_body .city_sort ul {
    padding-left: 10px;
    margin-top: 10px;
}
.city_body .city_sort ul li {
    line-height: 30px;
    line-height: 30px;
}
.city_body .city_index {
    width: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
    border-left: 1px #e6e6e6 solid;
}
</style>